ENGINE EMISSION CONTROLS

There are three sources of automotive pollutants: crankcase fumes, exhaust gases and gasoline evaporation. The pollutants formed from these substances can be grouped into three categories: unburned hydrocarbons (HC), carbon monoxide (CO) and oxides of nitrogen (NO
x
). The equipment that is used to limit these pollutants is commonly called emission control equipment.

Fig. Fig. 1: The vehicle emission control information label includes instructions for engine control system adjustment